Anatomic study for ideal and safe posterior C1-C2 transarticular screw fixation
Anatomic study for ideal and safe posterior C1-C2 transarticular screw fixation
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DOI：
10.1097/00007632-199808010-00018
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发表时间：
1998-08-01
期刊：
影响因子：
3
通讯作者：
Jun, BY
中科院分区：
文献类型：
--
作者：
Jun, BY
研究设计。采用客观测量方法测量C1-C2后经关节螺钉轨迹的最长路径或违反横孔的方向。 目的。明确螺钉轨迹的方向，标记最长的路径，而不侵犯横孔。为了实现这一目标，通过测量 C2 上关节面上螺钉交叉点的位置来客观化螺钉轨迹的不同方向。背景数据摘要。后 C1-C2 后经关节螺钉固定的主要限制是椎动脉的位置。由于缺乏客观的测量方法，18%至23%的病例根据个人经验来决定是否适合手术。方法。在距椎管 3.5 毫米和 6 毫米处制作矢状重建计算机断层扫描图像。绘制出最长路径或违反横孔（危险轨迹）的C2-C2经关节螺钉轨迹，并从C2上关节面后缘测量它们在C2上关节面上的螺钉交点。当危险轨迹的螺钉交点后面的螺钉可用空间I：等于或小于3.5mm时，该情况被定义为“不可接受”；当可供螺钉使用的空间大于3.5毫米但等于或小于4.5毫米时，则将螺钉的放置定义为“有风险”。结果。在 3.5 毫米横向图像和 6 毫米横向图像中，当轨迹分别经过 C2 后关节面后缘平均 3.6 毫米和 2.8 毫米时，轨迹形成最长路径。 64 例中有 4 例单侧 3.5 毫米侧位图像不可接受或有风险，21 例单侧 6 毫米侧位图像不可接受或有风险。随着螺钉轨迹的前倾角的增加，我们注意到风险的 S 形增量曲线。结论。明确了 C2 上关节面上与轨迹相交的区域，在不违反横孔的情况下形成最长路径，作为理想和安全轨迹的指南，还提出了后 C1-C2 经关节螺钉固定的理论最小风险和常见风险。
Study Design. Directions of the C1-C2 posterior transarticular screw trajectories making the longest path or violating the transverse foramen were measured by using an objective measuring method.Objectives. To clarify the directions of the screw trajectory marking the longest paths without violating the transverse foramen. To achieve this, diverse directions of the screw trajectories were objectified by measuring the locations of the points of screw intersection on the superior articular surface of C2.Summary of Background Data. The principal limitation of posterior C1-C2 posterior transarticular screw fixation is the location of the vertebral artery. Because of the lack of an objective measuring method, surgical unsuitability has been decided on the basis of individual experiences as reported in 18% to 23% of cases.Methods. Sagittal reconstructed computed tomographic images were made at 3.5 mm and 6 mm from the spinal canal. C2-C2 transarticular screw trajectories making the longest path or violating the transverse foramen (dangerous trajectory) were drawn, and their points of screw intersection on the superior articular surface of C2 were measured from the posterior rim of the superior articular surface of C2. When the space I: available for the screw behind the points of screw intersection by the dangerous trajectory was equal to or less than 3.5 mm, the case was defined as "unacceptable"; wen the space available for the screw was more than 3.5 mm but equal to or less than 4.5 mm, it was defined as "risky" for the placement of the screw.Results. Trajectories make the longest paths when they pass an average of 3.6 mm and 2.8 mm anterior to the posterior rim of the posterior articular surface of C2 at 3.5-mm lateral images and 6-mm lateral images, respectively. Four of 64 cases were unacceptable or risky unilaterally on 3.5-mm lateral images, and 21 cases were unacceptable or risky on 6-mm lateral images. A sigmoid-shaped increment curve of the risk was noted as the increasing forward inclination of the screw trajectories increased.Conclusions. The areas on the superior articular surface of C2 intersected by the trajectories making the longest paths without violating the transverse foramen are clarified as a guide to the ideal and safe trajectories, The theoretical minimal risk and usual risk of the posterior C1-C2 transarticular screw fixation are presented as well.